Papers - AYABE Takanori
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Surgical Management of Ductus Arteriosus Aneurysm in Adults Reviewed
Takanori Ayabe, Kunihide Nakamura, Seiji Nakajima, Yoshikazu Yano, Yasunori Matsuzaki, and Toshio Onitsuka
Jpn. J. of Thoracic and CardioVasc. Surg 48 304 - 306 2000.1
Language：English Publishing type：Research paper (scientific journal)
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The reaction mechanism of human adenylate kinase. The steady-state kinetics of the mutants constructed by protein engineering of site-directed mutagenesis. Recent Res. Devel. Biochem., Research Signpost (India), 2: 1-39, (2000) Reviewed
Ayabe T. and Hamada M.
Recent Res. Devel. Biochem 2 1 - 39 2000.1
Language：English Publishing type：Research paper (other academic)
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Ayabe T., Park S.K., Takenaka H., Takenaka O., Maruyama H., Sumida M., Onitsuka T., Hamada M.
Journal of Biochemistry 128 ( 2 ) 181 - 187 2000
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Biochemistry
To elucidate whether the C-terminal region in human adenylate kinase participates in the interaction with the substrate (MgATP2- and/or AMP2-), hydrophobic residues (Val-182, Vall86, Cys187, Leu190, and Leu193) were substituted by site-directed mutagenesis and the steady-state kinetics of fifteen mutants were analyzed. A change in the hydrophobic residues in the C-terminal domain affects the affinity for substrates (K(m)), that is, not only for MgATP2- but also for AMP2-, and the catalytic efficiency (k(cat)). The results obtained have led to the following conclusions: (i) Val182 may interact with both MgATP2- and AMP2- substrates, but to a greater extent with MgAT2-, and play a role in catalysis. (ii) Val186 appears to play a functional role in catalysis by interacting with both MgATP2- and AMP2- to nearly the same extent. (iii) Cys187 appears to play a functional role in catalysis. (iv) Leu190 appears to interact with both MgATP2- and AMP2- substrates but to a greater extent with AMP2-. (v) Leu193 appears to interact with both MgATP2- and AMP2- but to a greater extent with AM2-. The activity of all mutants decreased due to the change in substrate-affinity. The closer the residue is located to the C-terminal end, the more its mutation affects not only MgATP2- but also AMP2- substrate binding. The hydrophobic alterations disrupt hydrophobic interactions with substrates and that might destabilize the conformation of the active site. The more C-terminal part of the α-helix appears to interact with AMP, as if it has swung out and rotated to cover the adenine moieties. The C-terminal α-helix of human adenylate kinase appears to be essential for the interaction with adenine substrates by swinging out during catalysis.
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Ayabe T., Matsuzaki Y., Edagawa M., Asado M., Onitsuka T.
Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia 5 ( 5 ) 331 - 335 1999.10
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia
For an inoperative critical airway obstruction (bilateral bronchial stenoses) from a carcinomatous carina due to the mediastinal lymphnodal metastasis from uterine cancer, we succeeded in improving the patient's severe dyspnea by the combination of bilateral bronchial stent dilatation and a percutaneous cardiopulmonary support (PCPS) system. The imminent airway stenosis with severe dyspnea may have a high risk of asphyxia and contact-flooding during implanting of the stent. By the novel use of PCPS in advance for blood-oxygenation as a respiratory support, we could safely perform the interventional therapy of bronchial expandable metallic stents, and the patient obtained a good quality of life without dyspnea until she died of systemic metastatic cachexia. This technique may possibly be approved as an option for temporary remission therapy of a critical airway obstruction.
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Immunohistochemical analysis of nm23-H1 gene product in node-positive lung cancer and lymph nodes Reviewed
Masaki Tomita, Takanori Ayabe, Yasunori Matsuzaki, Toshio Onitsuka
Lung Cancer 24 11 - 16 1999.5
Language：English Publishing type：Research paper (scientific journal)
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Immunohistochemical analysis of nm23-H1 gene product in node-positive lung cancer and lymph nodes
Tomita M., Ayabe T., Matsuzaki Y., Onitsuka T.
Lung Cancer 24 ( 1 ) 11 - 16 1999.4
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Lung Cancer
The nm23-H1 gene product has been considered as an anti-metastatic protein and the level of its expression has been reported to correlate inversely with metastatic potential in some cancers. However, the expression of nm23-H1 gene product in the metastatic sites have not been studied in detail. We examined the expression of nm23-H1 gene product in surgically resected 46 pairs of primary lung cancers and metastatic lymph nodes by immunohistochemistry. The positive staining of nm23-H1 gene product in primary cancers and metastatic lymph nodes were observed in 56.5 and 67.4%, respectively. The heterogeneity of nm23-H1 gene product expression between primary cancers and metastatic lymph nodes was observed in 41.3%. No correlations were found between the nm23-H1 gene product expression in lung cancers and the patients survival. No significant association was also observed between nm23-H1 gene product expression in lymph nodes and the patients survival. There was, furthermore, no correlation between the heterogeneity of nm23-H1 gene product expression and the patients survival. In conclusion, the level of nm23-H1 gene product expression does not significantly reveal prognostic value in node-positive lung cancers. Expression of nm23-H1 gene product in metastatic lymph nodes was also unrelated to patients survival. Copyright (C) 1999 Elsevier Science Ireland Ltd.
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A Novel Interventional Therapy Using the Combination of Bilateral Bronchial Stent Dilatation and Percutaneous Cardiopulmonary Support for Critical Airway Obstruction due to Metastatic Carcinomatous Carina Reviewed
Takanori Ayabe, Yasunori Matsuzaki, Masao Edagawa, Mikio Asado, and Toshio Onitsuka
Anｎ Thorac Cardiovasc Surg 5 331 - 335 1999.2
Language：English Publishing type：Research paper (scientific journal)
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Site-directed mutagenesis and steady-state kinetic analysis of mutant enzymes of human adenylate kinase Reviewed
Takanori Ayabe, Seung Kyu Park, Hiroyuki Nagahama, Hideharu Maruyama, Michihiro Sumida, Hitoshi Takenaka, Osamu Takenaka, Toshio Onitsuka, and Minoru Hamada
Biochemistry and Molecular Biology International 46 673 - 680 1998.2
Language：English Publishing type：Research paper (scientific journal)
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Ayabe T., Park S.K., Nagahama H., Marayama H., Sumida M., Takenaka H., Takenaka O., Onitsuka T., Hamada M.
Biochemistry and Molecular Biology International 46 ( 4 ) 673 - 680 1998
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemistry and Molecular Biology International
Site-directed mutagenesis of human adenylate kinase (AK) was carried out on residues His36, Lys55, and the C-terminal segment (Val182, V186, and Leu 193). Five mutants ((H36T, K55G, V182G, V186S, and L193Stop (deletion of residues 193-194)) were generated and analyzed by steady-state kinetics. H36T, K55G, and L193Stop mutants showed an increase of K(m) values (19.8-, 19.7-, and 11.3-fold) for AMP2- compared to that for the wild-type enzyme, and these residues appeared to interact with AMP2-. V182G showed an increased K(m) value (7.4-fold) for MgATP2-. Therefore, V182 may be essential for interaction with MgATP2-. V186S increased the K(m) value (7.0- and 7.5-fold) for MgATP2- and AMP2-. V186 may thus interact with both substrates. The C-terminal domain of AK appears to be essential for MgATP2- and AMP2- binding.
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Takanori Ayabe, H. Takenaka, O. Takenaka, M. Sumida, M. Hideharu, T. Onitsuka, K. Shibata, S. Uesugi, and M. Hamada
Biochemistry 36 4027 - 4033 1997.10
Language：English Publishing type：Research paper (scientific journal)
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Ayabe T., Takenaka H., Takenaka O., Sumida M., Maruyama H., Onitsuka T., Shibata K., Uesugi S., Hamada M.
Biochemistry 36 ( 13 ) 4027 - 4033 1997.4
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemistry
To elucidate the minimum requirement of amino acid residues for the active center in human adenylate kinase (hAK1), we carried out random site- directed mutagenesis of key lysine residues (K9, K21, K27, K31, K63, K131, and K194), which were conserved in mammalian AK1 species, with the pMEX8- hAK1 plasmid [Ayabe, T., et al. (1996) Biochem. Mol. Biol. Int. 38, 373- 381]. Twenty different mutants were obtained and analyzed by steady-state kinetics, and all mutants showed activity loss by K(m) and/or k(cat) effects on MgATP2-, AMP2-, or both. The results have led to the following conclusions. (1) Lys9 would appear to interact with both MgATP2- and AMP2- but to a larger extent than with AMP2-. (2) Lys21 is likely to play a role in substrate binding of both MgATP2- and AMP2- but more strongly affects MgATP2- . (3) Lys27 and Lys131 would appear to play a functional role in catalysis by interacting strongly with MgATP2-. (4) Lys31 would appear to interact with MgATP2- and AMP2- at the MgATP2- site. (5) Lys63 would be more likely to interact with MgATP2- than with AMP2-. (6) Lys194 in the flanking C-terminal domain would appear to interact not only with MgATP2- but also with AMP2- at the MgATP2- site by stabilizing substrate binding. The loss of the positively charged ε-amino group of lysine affects both the affinity for the substrate and the catalytic efficiency. Hence, hydrophilic lysine residues in hAK1 would appear to be essential for substrate-enzyme interaction with the coordination of some arginine residues, reported previously [Kim, H. J., et al. (1990) Biochemistry 29, 1107-1111].
DOI： 10.1021/bi961796a
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Substrate-Binding and Catalytic Roles of Lys194 In the C-terminus in Human Adenylate Kinase by Site-directed Random Mutagenesis Reviewed
Takanori Ayabe, H. Takenaka, O. Takenaka, T. Onotsuka, K. Shibata, S. Uesugi, and M. Hamada
Biochemistry and Molecular Biology International 41 367 - 375 1997.2
Language：English Publishing type：Research paper (scientific journal)
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Ayabe T., Takenaka H., Takenaka O., Onitsuka T., Shibata K., Uesugi S., Hamada M.
Biochemistry and Molecular Biology International 41 ( 2 ) 367 - 375 1997.2
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemistry and Molecular Biology International
Site-directed random mutagenesis of Lys194 residue in the C-terminus of human adenylate kinase (AK) was performed, and six mutants were analyzed by steady-state kinetics. K194-mutants variously affected the apparent Michaelis constants (K(m) values) for ATP and AMP, although the k(cat) values strikingly decreased. The Lys194 residue appears to interact not only with MgATP2- but also with the AMP2- substrates by salt bridge formation with a nucleotide and to play a functional role in stabilizing the phosphate-transfer during catalysis. Lys194 could be essential for substrate-holdings and in catalysis and not replaceable to the other amino acids.
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Catalytic roles of Lysines (K9, K27, K31) in the N-terminal domain in human adenylate kinase by random site-directed mutagenesis. Reviewed
Takanori Ayabe, S. K. Park, H. Takenaka, M. Sumida, S. Uesugi, O. Takenaka, and M.Hamada
Biochemistry and Molecular Biology International 40 897 - 906 1996.12
Language：English Publishing type：Research paper (scientific journal)
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Construction of the plasmid pMEX8-hAK1 and random site-directed mutagenesis of human cytosolic adenylate kinase. Reviewed
Takanori Ayabe, Hitoshi Takenaka, Osamu Takenaka, Akiko Takenaka, Hiroyuki Nagahama,Hideharu Maruyama, Atsushi Yamamoto, Masahiko Nagata, Yasunori Koga, Michihiro Sumida, and Minoru Hamada
Biochemistry and Molecular Biology International 38 373 - 381 1996.12
Language：English Publishing type：Research paper (scientific journal)
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Site-directed random mutagenesis of the c-terminal residue (K194) of human adenylate kinase
Ayabe T., Takenaka H., Maruyama H., Koga Y., Hamada M.
FASEB Journal 10 ( 6 ) 1996.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：FASEB Journal
Human adenylate kinase (AK) consisting of 194 amino acid residues is a ubiquitous enzyme which catalyzes the reaction: MgATP2- + AMP2MgADP- + ADP-. The Lys 194 was substituted by site-directed random mutagenesis of the pMEX8-hAKl vector. Six mutants, K194S, K194I, K194L, K194P, K194N, and K194V, were obtained and steady-slate kinetics showed interesting results. The Km value of K194S was increased (14.7fold) for MgATP2- and that of K194V was increased (20.6-fold) for AMP2compared to those of wild type AK. On K1941 and K194N, the Km values were not changed (0.6 -1.6 fold) for AMP2-, this is not a significant change, however, the Vmax values were decreased (less 5%). On K194L, the Km value was increased (9.7-fold) for MgATP2- and the kcat/Km value was decreased (0.01%), even though the Km value for AMP2- was dramatically decreased (0.05-fold) and the kcal/Km value was increased (5.2-fold). Lys 194 residue might specifically affect either of the MgATP2 or AMP2substrates while the C-terminal domain was deduced to locate closely to MgATP2- binding site in the X-ray model. The flexible C-terminal domain might play an important role in catalysis by moving and holding the substrates therby facilitating the reaction. Lys 194 may be essential for the C-terminus to play this role in the enzyme molecule.
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Ayabe T., Takenaka H., Takenaka O., Takenaka A., Nagahama H., Maruyama H., Yamamoto A., Nagata M., Koga Y., Sumida M., Hamada M.
Biochemistry and Molecular Biology International 38 ( 2 ) 373 - 381 1996.8
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemistry and Molecular Biology International
The pMEX8-hAK1 vector was devised from the pAK plasmid, which could directly express human adenylate kinase proteins without recombination and its single strand DNA could be withdrawn with helper phage for random site-directed mutagenesis. The conserved key residues at Lys21, Lys27, and Thr39 were engineered to obtain mutants for kinetic analysis. Three mutants were obtained as K21P, K27R, and T39S, their specific activities were strikingly reduced compared to those of wild type adenylate kinase. This pMEX8-hAK1 will be a powerful tool for site-directed mutagenesis to detect the substrate-enzyme interaction for human adenylate kinase including various other enzymes.
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Steady-state Kinetics of Thr35- and Thr39-mutants in Human Adenylate Kinase by Site-directed Mutagenesis Reviewed
Takanori Ayabe, H. Takenaka, T. Onitsuka, K. Shibata, O. Takenaka, S. Uesugi, and M. Hamada
Enzyme & Protein 49 305 - 312 1996.5
Language：English Publishing type：Research paper (scientific journal)
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Site-directed random mutagenesis of the c-terminal residue (K194) of human adenylate kinase Reviewed
Ayabe, T., Takenaka, H., Maruyama, H., Koga, Y., Hamada, M.
FASEB Journal 10 ( 6 ) A1103 1996.2
Language：English Publishing type：Research paper (scientific journal)
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Ayabe T., Park S.K., Takenaka H., Sumida M., Uesugi S., Takenaka O., Hamada M.
Biochemistry and Molecular Biology International 40 ( 5 ) 897 - 906 1996
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemistry and Molecular Biology International
To elucidate lysine residues in the N-terminal domain of human cytosolic adenylate kinase (hAK1, EC 2.7.4.3), random site-directed mutagenesis of K9, K27, and K31 residues was performed, and six mutants were analyzed by steady-state kinetics. K9 residue may play an important role in catalysis by interacting with AMP2-. K27 and K31 residues appear to play a functional role in catalysis by interacting with MgATP2-. In human AK, the ε-amino group in the side chain of these lysine residues would be essential for phosphoryl transfer between MgATP2- and AMP2- during transition state.